Effect of Genotype, Growing Year and Planting Date on Agronomic Traits and Chemical Composition in Sunflower (Helianthus annuus L.) Germplasm

Sunflower is one of the most widely cultivated oil crops. It produces seeds which have abundant health benefits. The objective of this research was to determine the effects of two growing years and five planting dates on agronomic traits and chemical compositions in sunflower accessions. In this study, genotype by year interaction was significant for days to flowering, weight of seeds per plant, oil, palmitic acid, stearic acid, oleic acid, linoleic acid, all tocopherol and phytosterol components. The major source of variation in most agronomic traits and chemical compositions in sunflower was attributed by variation among genotypes. Days to flowering, head length, and weight of seeds per plant decreased when planting date was delayed. Oil content, stearic acid, oleic acid, α -tocopherol, total tocopherol, β-sitosterol, and total sterol contents decreased but linoleic acid increased when planting date was delayed. From this study, valuable information will be provided for sunflower breeders and growers in developing and producing functional food resources and products.